Practical Guide to Serial Communication in Keil5: UART, I2C, SPI

# 1. Introduction to Keil5

## 1.1 Basic Overview of Keil5
Keil5 is a professional embedded development tool, developed by the German Keil Software company, designed to provide an efficient development environment for embedded systems. Keil5 integrates C/C++ compilers, debuggers, and emulators, supporting multiple mainstream processor architectures, including ARM, 8051, C166, etc. Developers can use Keil5 to code, compile, debug, and emulate, quickly and accurately developing embedded systems.

## 1.2 Installation and Configuration Methods of Keil5
To use Keil5 for embedded development, it is necessary to install and configure it correctly. Here are the basic steps for installing and configuring Keil5:
1. Download the Keil5 installer from the official website and run the installer.
2. After installation, open Keil5, create a new project, and select the target processor type.
3. Configure the project's compiler and debugging options, ensuring the project settings are correct.
4. Write code and compile, then check the compilation output results.
5. Use the emulator provided by Keil5 or an external debugger to connect to the target device, and perform debugging and testing.

By following these steps, you can successfully install, configure, and begin using Keil5 for embedded software development. In the following chapters, we will delve into the practical guidelines for serial communication in Keil5 to help you better apply serial communication technology in embedded systems.

# 2. Basics of Serial Communication

Serial communication is a common data transmission method, particularly suitable for communication between microcontrollers and external devices. This chapter will introduce the principles and applications of serial communication, as well as the methods for configuring and practicing UART serial communication in Keil5.

### 2.1 Principles and Applications of Serial Communication

Serial communication is a method of transmitting data through serial communication, which, in comparison to parallel communication, requires fewer lines and simpler wiring. Serial communication is commonly used for data interaction between microcontrollers and external devices such as sensors, displays, and wireless modules, and it is a common communication method in embedded systems.

### 2.2 Introduction and Configuration of UART Serial Communication

UART (Universal Asynchronous Receiver/Transmitter) is a common serial communication protocol that transmits data asynchronously, transferring data bits between start and stop bits, typically using a pair of pins (TX and RX) for data transmission. Configuring UART serial communication in Keil5 requires setting parameters such as baud rate, data bits, and parity bits.

### 2.3 Practical Cases of UART Serial Communication

Below is a simple example code using Python to simulate UART serial communication:

import serial

ser = serial.Serial('COM1', 9600, timeout=1)   # Open serial port
ser.write(b'Hello, UART!')   # Send data
data = ser.readline()   # Read data
print(data)   # Output the received data

ser.close()   # Close serial port

With the above code, we can achieve operations such as opening the serial port, sending and receiving data, and closing the serial port. Such practical cases help deepen the understanding of UART serial communication.

# 3. I2C Communication Practice

I2C communication is a common serial communication interface suitable for connecting various peripherals and sensors. Configuring I2C communication in Keil5 is crucial to ensure normal communication between devices. This chapter will introduce the basic principles of the I2C communication protocol, the steps to set up I2C communication in Keil5, and a simple example of I2C communication application.

#### 3.1 Introduction to the I2C Communication Protocol

I2C (Inter-Integrated Circuit) is a two-wire serial communication protocol consisting of three main signal lines: the clock line (SCL), the data line (SDA), and the ground line. In I2C communication, each device has a un